Improvement in steam-boilers



G. MANN.

ML MJ 1,

No. 221,837. Patented Nov.18, 1879.

UNITEo STATES PATENT OEETGE,

GEORGE MANN, or BUFFALO, NEwMYORK.

IMPROVEMENT IN STEAM-BOILERS".

Specification forming part of Letters Patent No. 221,837, (lated'ovember18, 1879 application filed l August 26, 1879.

Y course from the furnace to the chimney.

The object of my invention is to establish a circulation of the hotgases through the tlues or tubes and back to the furnace, where the hotgases are mixed with fresh air and brought in contact with the flame,and thus are completely burned or consumed before they are permitted toescape into the chimney.

My invention consists in the combination,

y with the lues of a steam-boiler, of a centrifugal fan, arranged todraw the unconsumed' gases from the lues and discharge the same into thefurnace, where they arebrought in contact with the ilame and consumed;also, in the combination, with the circulating flues leading back to thefurnace, of auxiliary flues leading to the chimney, whereby a constantdraft through the latter is maintained; also, in certain details ofconstruction of the nues, as willbe hereinafter more fullyv set forth 5also, ina perforated steam -pipe arranged transversely in thefire-passage, so as to throw jets of superheated steam toward the flame,whereby the intensity of combustion is increased.

In the accompanying drawings, consisting of twosheets, Figure 1 is alongitudinal section of a steam-boiler provided with my improvements,the section being taken in line .r x, Fig. 4. Fig. 2 is a frontelevation thereof. Fig. 3 is a longitudinal section in line y y, Fig. 4.Fig. 4 is a cross-section in linezzof Fig. 3.

Like letters of reference refer to like parts in the several figures.

A represents a horizontal cylindrical steamboiler; B, the fire-chamber;G, the grate; D, the ash-pit; E, the fire wall or bridge; F, thechimney, and F the damper. G Gr represent two auxiliary lues, arrangedcentrally in the boiler, the lower flue, G, leading from the firepassagebelow the damper F to the smokebox H at the front of the boiler, and theupper flue, G', leading from the smoke-box II to the chimney F. i

I I represent the circulating-fines, arranged in horizontal rows on bothsides of the central lines, G G. The circulating-fines are connected atthe front of the boiler by smoke-boxes J J J 2, and at the rear of theboiler by smokeboxes K K K2, in such manner that the hot gases enter thelower tier or row of fines, I, at the rear of the boiler, and travelthrough the same to the front thereof and into the lower smoke-box, J,whence the gases pass into the second tier of flues, I', and travelthrough the same to the rear end of the boiler and into the lowersmoke-box, K. From there the gases pass successively forward andbackward through the remaining tiers of circulatingtlues I Il andsmoke-boxes J J2 K K2, :and are finally discharged into the uppersmoke-box, L, at the front ofthe boiler. The smoke-chambers J J J2 aresecured together and hinged to the upper smoke-chamber, L, so that theycan be swung upwardly out of the waywhen access to the flues is desiredfor cleaning or repairing the same. The rear smokechambers, K K K2, aresimilarly constructed and hinged to the boiler at k.

M is a centrifugal fan, having its eyes or suction-openings connectedwith the smokebox L, so as to Vwithdraw the hot gases therefrom. m isthe discharge-spout of the fan M, which leads downward to the furnaceand discharges the hot gases below the grate. The fan M is rotated by abelt running over a pulley, n, or by any other' suitable means.

o is a steam-pipe connecting with the steamspace of the boiler, andhaving its discharge end lo arranged transversely in the fire-passageabove the fire-bridge E, so that it becomes highly heated by the amepassing over and around it. The discharge end p is provided withperforations on its rear side, through which jets of steam are thrownagainst the flame. The steam becomes superheated by -contact with theheated pipe before it escapes through the perforations, and isconsequently in a dry and gaseous form when discharged into the llame,and assists greatly in intensifying the combustion.

In starting the lire under the boiler the damper F may be opened, whenthe draft will 2YSheets-Sheet l.

G. MrcBRIDE. Tellurian. N10. 221,838; Patented NQV. 18, 1879.-

BY /U/WA/ mms@Je NAPTERS. PHoTO-LITHGGRAPMEN, WASHINGTON. D C,

